package com.jjwxc.jwjskandriod.readActivity.utils;

import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;

import com.jjwxc.jwjskandriod.R;
import com.jjwxc.jwjskandriod.config.YtApplication;

/**
 * Created by Administrator on 2016/7/29 0029.
 */
public class BitmapUtil {
    public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId,
                                                         int reqWidth, int reqHeight) {

        // First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(res, resId, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        return BitmapFactory.decodeResource(res, resId, options);
    }

    public static int calculateInSampleSize(
            BitmapFactory.Options options, int reqWidth, int reqHeight) {
        // Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = -1;

        if (height > reqHeight || width > reqWidth) {

            final int halfHeight = height / 2;
            final int halfWidth = width / 2;

            // Calculate the largest inSampleSize value that is a power of 2 and keeps both
            // height and width larger than the requested height and width.
            while ((halfHeight / inSampleSize) > reqHeight
                    && (halfWidth / inSampleSize) > reqWidth) {
                inSampleSize *= 2;
            }
            final int heightRatio = Math.round((float) height / (float) reqHeight);
            final int widthRatio = Math.round((float) width / (float) reqWidth);
            // 选择宽和高中最小的比率作为inSampleSize的值，这样可以保证最终图片的宽和高
            // 一定都不会大于等于目标的宽和高。
            inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;

        }

        return inSampleSize;
    }

    public static Bitmap getBgBitmap(int pos, int mViewWidth, int mViewHeight) {
        Drawable drawable;
        if (pos == 0) {
            drawable = YtApplication.getInstance().getResources().getDrawable(R.mipmap.theme_bg_one);
        } else if (pos == 1) {
            drawable = YtApplication.getInstance().getResources().getDrawable(R.mipmap.theme_bg_two);
        } else if (pos == 2) {
            drawable = YtApplication.getInstance().getResources().getDrawable(R.mipmap.theme_bg_three);
        } else {
            return null;
        }
        BitmapDrawable bd = (BitmapDrawable) drawable;
        final Bitmap bmm = bd.getBitmap();
// 获得图片的宽高
        int width = bmm.getWidth();
        int height = bmm.getHeight();
        // 计算缩放比例
        float scaleWidth = ((float) mViewWidth) / width;
        float scaleHeight = ((float) mViewHeight) / height;
        // 取得想要缩放的matrix参数
        Matrix matrix = new Matrix();
        matrix.postScale(scaleWidth, scaleHeight);
        // 得到新的图片
        return Bitmap.createBitmap(bmm, 0, 0, width, height, matrix, true);
    }
}

